Fundamentals of Refrigeration: Area

The area is the number of square units that can fit within a two-dimensional, or flat, space. To find the area of a two-dimensional square or rectangular surface, one must first measure the length of each side. Once those measurements are obtained, the formula A=LxW will calculate the area of the surface.

Example: If a table had the length of 5 feet and the width of 2 the Area of the table would be 10 square feet.

Thinking of Area as a square measure is important; it can be visualized by imagining 1-foot squares filling a table. It is then obvious that 10 1-foot squares fit onto the surface of the table. This is where the expression square feet comes from. The table would have a surface area of 10 square feet.

When calculating area, the final answer must include the correct units. A common unit of area is “Square Feet”, which is typically written with the ‘2’ displayed as an exponent, which in math language means that the number has been squared. The term “squared” means that the number is multiplied by itself. For example, 4 squared means 4 x 4, which equals 16. Square inches, square miles, and square meters are other common units of area measurement.

 

It is important to correctly account for all units when performing mathematical calculations. A common mistake is for two different units to be multiplied by each other when calculating area. For example, if a rectangle is 24 inches wide by 6 feet long, one of the units must first be converted before multiplying.

Calculating the area of a circle is the same concept, but the math is a bit more challenging because circles do not have straight lines.

Before learning how to calculate the area of a circle, we must define a few terms. The “diameter” of a circle is the linear distance between any two points on a circle that passes through the center of the circle.

The “radius” of a circle is exactly one-half of the diameter.

The “circumference” of a circle is the length of the boundary of a circle. Put another way, if you could cut a circle and lay it out flat, the circumference would be the length of the line.

Another important term to be familiar with when working with circles is “Pi”. Pi is a number that is equal to the ratio of the circumference of any circle to its diameter. Most calculators have a special key for pi, but its numeric value can also be approximated as 3.14.